The invention relates to a cap for a seat belt retractor. The invention also relates to a seat belt retractor equipped with such a cap.
An important factor in the performance of a seat belt retractor is the noise generated by the retractor. The locking mechanism of a seat belt retractor contains a number of movable parts, which cause the noise in the driving operation. Particularly when the locking mechanism contains a sensor having a movably disposed element for the vehicle-sensitive triggering of the locking mechanism, the sensor is continuously deflected as a result of vibrations during driving and thereby strikes against other parts.
The significance of a low-noise seat belt retractor rises if the retractor is installed in a seat and is arranged close to the upper part of the seat, which brings the retractor very close to a vehicle occupant's ear.
Although, for avoiding such buzzing and rattling noises, the manufacturers of retractors offer components for quieting the sensor mass in the form of wire clamps or the like, these solutions are usually effective only when the seat belt is not worn.
From German patent document DE 42 31 050 A1, a retractor is known which is arranged within a cavity of a column of a motor vehicle. The retractor includes an automatic belt retracting device as well as a belt tightening device. The automatic belt retracting device is enclosed by a housing which includes a base plate. The base plate, on the cavity side, rests against the inside panel of the column and is fastened to the inside panel by use of a single screw. In order to prevent the transmission of structure-borne noise from the automatic retracting device to the column, in the case of the known retractor, a sleeve-shaped elastomer part is provided between the screw, on the one hand, and the inside panel or the base plate, on the other hand.
From German patent document DE 91 10 869.1 U1, a seat belt retractor is known which is equipped with a housing lid constructed as a plastic molded part with a base wall. A plurality of elevations cast to the base wall are provided, which taper in the forming-out direction of the housing lid and form a sound-absorbing labyrinth structure.
It is an object of the invention to reduce the noise of a seat belt retractor in an easily implemented manner.
According to the invention, this object is achieved by providing a cap for a seat belt retractor having a housing, which cap can be placed on a side of the housing of the seat belt retractor that is assigned to a sensor. The cap is made of aluminum and is provided with an adhesive plate, by which the cap is glued to the housing. Advantageous further developments are described and claimed herein.
The cap according to the invention consists of aluminum and is provided with an adhesive plate by way of which the cap is glued onto a housing of the seat belt retractor. The noise generated by the sensor of the seat belt retractor is reduced by the cap having the adhesive plate.
In an advantageous embodiment, the adhesive plate consists of an elastomer, particularly of a butyl adhesive. The butyl adhesive has good noise reduction characteristics and a good stability with respect to acid and alkali.
Additional advantages and further developments of the invention are contained in the following description and the attached drawings.
It is understood that the above-mentioned characteristics which will be explained in the following can be used not only in the respectively indicated combination but also in other combinations or alone without leaving the scope of the present invention.
The invention is schematically illustrated in the drawings by means of several embodiments and will be described in detail in the following with reference to the drawings.